Spring Temp Exceedance Review
Erin Cain
4/14/2021
Spring Temperature Exceedance Analysis
Using delta temperature data we examined the frequency of temperatures in March and April being >= 15°C and >= 17°C respectively for two strata (Yolo Bypass and Sacramento River). We used water year type data from WaterYearType and filtered to include only location == "Sacramento Valley".
We first summarized the data to daily averages and then calculated the following:
- water_year: water year (Oct-Sept)
- water_year_type: water year type (Critical, Dry, Below Normal, Above Normal, Wet)
- month: month
- stat: summary statistic
- prop_above_threshold: number of days over threshold divided by number of days with observations
- n: number of observations within the water_year/month combination
- min_temp: minimum temperature within the water_year/month combination
- max_temp: maximum temperature within the water_year/month combination
- mean_temp: mean temperature within the water_year/month combination
- first_day_exceeded: the day that the temperature first exceeded the temperature threshold
- value: value
The summarized data is saved in cache_slough_temp_exceeding_tresholds_long.csv.
March Temp Exceedance
March Proportion Temp Exceedance of Threshold by Water Year Type I calculated the mean proportion above threshold for each water year type by grouping by water_year_type and then calculating the mean of the prop_above_threshold column.
| Water Year Type | Mean Prop Above Threshold |
|---|---|
| Critical | 0.3514310 |
| Dry | 0.2427273 |
| Below Normal | 0.1211111 |
| Above Normal | 0.0666667 |
| Wet | 0.0645833 |
Figures
April Temp Exceedance
April Proportion Temp Exceedance of Threshold by Water Year Type
| Water Year Type | Mean Prop Above Threshold |
|---|---|
| Critical | 0.5272894 |
| Dry | 0.3085017 |
| Below Normal | 0.3230159 |
| Above Normal | 0.0000000 |
| Wet | 0.1799479 |
Figures
